Reversing gear for two-stroke cycle internal-combustion engines



Jan. 22; 1924.

H. MICHEL REVERSING GEAR FOR TWO-STROKE CYCLE INTERNAL COMBUSTION ENGINES Filed Oct. 26. 1922 .5 J WM" Patented Jan. 22, I924.

' HERMANN MICHEL, ornotsrnrn, GERMANY.

BEVEBSING GEAR FOR TWO-STROKE CYCLE INTERNAL-GOIIIBUSTIQN ENGINES.

Application filed October 26, 1922. Serial No. 596,974.

To all whom it may concern:

Be it known that I, HERMANN MIoHnL, a citizen of Germany, and aresident of Voorde i. Holstein, Germany, have invented certain new and useful Improvements in.

Reversing Gears for Two-Stroke Cycle Internal-Combustion Engines, of which the following is a specification.

My invention relates to improvements in t0 reversing gears for two-stroke cycle internal combustion engines. In two-stroke cycle internal combustion engines the reversing mechanism comprises a cam shaft carrying cams for forward and rearward operation and adapted to be shifted for bringing either one of said cams into operative position. In other constructions the cam shaft is provided only with one set of cams, and it is adapted to be turned at a: suitable angle, which for example in engines of the Diesel type is about 80. The construction of the cam shaft and the mechanism for setting the sameangularly is complicated, so

much the more as it must be such as to per- 2 1nit setting while the engine is running. In addition the cams controlling the fuel supply and the starting mechanism must be turned at different angles.

In other constructions of two-stroke cycle combustion engines the cam disk is equipped with a single cam controlling the two-stroke cycle and cooperating 'with a rockablevalve lever adapted to be shifted longitudinally in a direction opposite to that of the cam for reversing the engine.

The angle through which the-lever is shifted relatively to the cam is about'SO". Therefore, the direction of the force exerted by the. camon the lever acts at large angle 40 :to the force of the spring of the valve acting 'tangential-ly of the fulcrum of the valve lever on the cam disk. This results in a high reaction on the valve gear and a heavy and reducing the number of revolutions of the cam disk'at the ratio of the number of the cams. Thereby the angle between the valve (not shown).

end positions of the valve lever or the antifriction roller carried thereby relatively to the cam disk is reduced at the ratio of the numbers of the cams, said angle being reduced for example in case of three cams from 30 to 10. In this case the direction of the reaction exerted by the cam disk and the direction, of the force caused by the valve spring and acting tangentially of the fulcrum of the val e lever are at an angle For the purpose of explaining the invention several examples embodying the same have been shown in the accompanying drawing, in which the same reference characters have been used in all the views to indicate corresponding parts. In said drawing,

Fig. 1, is a diagra-inmatical view of a system now in use and comprising a single cam on the steering shaft,

Fig. 2. is an elevation largely diagrammatic and partly in section showing my im proved reversing mechanism,

Fig. 8, is a sectional-elevation showing a. modification,

Fig. 4, is a plan view ofFig. 3,

Fig. 5, is an elevation showing another modification, and

Fig. 6, is a section taken on the line 6-43 of Fig. 5 and looking in the direction of the arrows. i I

In the construction shown in Fig. 1 illustrating a part of the steering mechanism of an engine of the Diesel type a single steering Cam 0 is provided on a disk 6 having rotary movement on a shaft a. The cam cooperates with a lever f carrying a roller 03 and adapted to operate the fuel admission For reversing the engine the lever f is shifted in longitudinal direction a distance corresponding to an angleoz of about 30. It the position of the axis of the roller (Z in case of forward movement is I and for backward movement II, the said angle or is disposed between the lines I--cv and .a-II.

In any position of the roller the direc- :tion of the radial reaction of the cam disk forms an angleof 15to the force caused by the valve spring and acti ,sversely of the fulcrum of the valve 1, so that. a strong reaction is caused.

As appears from 2', in my improved construction the cam disk 2 rotatable about the axis 1 ca -ries three cams displaced-with ed upon by a spring 12 tending to force the same on its seat. The lever 7, 9 is adapted to be shifted longitudinally of its length by suitable means. To show what may be done the lever'is mounted on a rocker 13 adapted to be rocked to the right or left in Fig. 2 for reversing the engine.

In the position shown in Fig. 2 in full lines the valve gear has been set for forward operation of the engine corresponding to the position I of the roller 6. The cam disk 2 rotates in the direction of the arrow shown in full lines. For reversing the engine the lever T, 9 is shifted in a-direction opposite to the rotation of the cams 4 and into the position II shown in dotted lines. The angle I1-II which corresponds to the displacement of the lever 7, 9 is about 10. Therefore, in both cases the position of the roller 6 is such that the direction of the radial reaction of the cam disk 2 and the direction of the force acting taingenliall of the fulcrum of the valve lever 7, 9 and exerted by the valve spring 12 are at an angle of 5, so that the reaction is reduced to a minimum.

In the modification shown in Figs. 3 and 4 the cam disk 2 is disposed perpendicularly to the valve lever 7, 9 acting on the valve 11, which construction is necessary in some cases in viewof other parts of the engine. In such cases the lever 7, 9 is rockingly mounted on an arm let mounted for rocking about the vertical axis of the valve 11'. As shown the arm 14 is provided with a hub 15 mounted on the valve casing 16. At its free end the arm 14: is formed with an eye 17 providing a bearing for a vertical pivot bolt 18 adapted to be rocked within said bearing and to be shifted therein in axial direction. At its bottom end the said pivot bolt carries the roller 6, and at its top end an axial pin 19 engaging the free end of the arm 7 On the eye 17 an arm 20' is rockingly mounted, and the pivot bolt 18 is non-rotatable but longitudinally shiftable within the hub of the said arm, for which purpose it is connected therewith for 0X' ample by a feather 20. The arm 20 is con nected by a link 21 parallelto the arm 7, 9 with a relatively fixed part of the frame 22 of the engine, the frame 22, the valve lever 7', 9', the arm 20, and the link 21 providing a parallel guide for holding the roller 6' in a plane parallel to the cam disk when rocking. the arm 14 for reversing the through the cam disk 2 and jointed to a' rocker 24 adapted to be rocked for shifting the roller relatively to the cams l in the manner described with reference to Figs. 1 to 4t. The top face of the lever 23 is in engagement with the valve lever 7 9 having its fulcrum at 8 When reversing the engine the lever 7 9 is rocked about its fulcrum 8 but otherwise its position is not varied, the lever 23 being free to be moved independently of the lever 7 9 and transversely thereof. The lever 23 can be com- 'paratively light andweak, because it has only the function to transmit the pressure from the roller 6 to the lever 7 9 While in describing the invention reference has been made to particular examples embodying the same I wish it to be understood that my invention is not limited to the constructions shown in the drawing, and that various changes may be made in the general arrangement of the apparatus and the construction of its parts without departing from the inventio i I claim:

1. In a valve gear for two-stroke cycle internal combustion engines, a valve, a cam disk carrying a plurality of cams for a plurality of cycles, and a valve operating lever adapted to be operated on one side of its fulcrum by said cams and the other side thereof being adapted to operate said valve and means for shifting said lever circumferentially of said disk.

2. In a valve gear for two-stroke cycle internal combustion engines, a valve, an arm movable about the axis of said Valve, a valve lever fulcrumed on said arm, and a cam disk carrying a plurality of cams for a plurality of cycles and disposed with its plane substantially perpendicular to said lever, said valve lever being in position for (DOPE-Nb tion with said cams and valve.

3. In a valve gear for two-stroke cycle internal combustion engines, the combination with the valve, of an arm movable about the Ill! - ternal combustion engines, a valve, a cam disc carrying a plurality of cams for a plurality of cycles, an arm movable about the axis of said valve and a lever fulcrumed on said arm adapted to operate said valve, and

10 in position for engagement with said cams.

5. In a valve gear for two-stroke cycle internal combustion en 'nes. a valve, a cam disc carrying a plurality of cams for a plurality of cycles, an arm movable about the axis of said valve, a lever carried by said arm and adapted to operate said valve and-a pivot bolt carried by said lever adapted to contact with said cams.

In testimony whereof I hereunto affix my signature.

HER-MANN MICHEL. [1,. s.] 

